function [Hy Hx p q] = prewittFilter(imageStruct)

% Hy: Vertical sobel frequency filter
% Hx: Horizontal sobel frequency filter

[Hy m n] = initFilterSize(imageStruct.image);
[Hx m n] = initFilterSize(imageStruct.image);

hy = fspecial('prewitt');
[c d] = size(hy);

p = m + c - 1;
q = n + d - 1;

fftStruct = doFFTDim(hy, p, q);
Hy = fftStruct.fftImage;

hx = hy';
fftStruct = doFFTDim(hx, p, q);
Hx = fftStruct.fftImage;
end